public class Example4_20 {
  public static void main(String args[ ]){
    char a[] ={'a','b','c','D','E','F'};
    for(int i=0;i<a.length;i++){
      if(Character.isLowerCase(a[i]))
        a[i]= Character.toUpperCase(a[i]);
        else if(Character.isUpperCase(a[i]))
        a[i]= Character.toLowerCase(a[i]);
    }
    for(int i=0;i<a.length;i++)
    System.out.print(" "+a[i]);
  }
}
